Elasticized leg and waist bands have gained increasing popularity in the areas of disposable applications, such as disposable diapers, incontinent pads and hospital gowns. A commercially viable approach for use on high speed production equipment was developed by Buell and disclosed in U.S. Pat. No. 4,081,301. According to this method, continuous bands of elastic, maintained in a stretched position, are glued or heat sealed onto the continuous web from which the disposable diapers are made.
Recognizing that greater efficiency could be achieved if the adhesion of the elastic band to the substrate did not require a separate adhesive or heating means, attempts have been made to prepare adhesives which exhibit the required degree of elasticity without sacrificing the necessary adhesive and cohesive properties. In U.S. Pat. No. 4,259,220, Bunnelle et al. proposed viscoelastic hot melt pressure sensitive compositions prepared from a rubbery block copolymer containing a rubbery polyisoprene midblock portion and a plurality of crystalline poly(vinylarene) endblocks; and two different resins, one of which is a tackifying resin compatible with the midblock and the other a reinforcing resin for the endblock portion of the copolymer.